1. Field of the Invention
The present invention relates to a novel method for effecting recovery of thermal values and production of organic materials, primarily paraffinic and non-paraffinic hydrocarbons, from solid carbonaceous fuels, i.e., bituminous coals and lignites, hereinafter at times collectively referred to as coals, by contacting such masses with foul condensates, i.e., black liquors, from pulping operations thereby unexpectedly solubilizing such materials (hereinafter generally referred to as thermal values) comprising and/or bound up in such coals.
2. Description of the Prior Art
Waste foul condensates, commonly called black liquors because of their dark color, result as an undesirable waste by-product from paper mill operations, both Kraft and non-kraft. Generally, these liquors are the condensate from evaporators and surface condensors associated with pulp digesters. These liquors heretofore have had no recognized use and their disposal in itself has been and continues to be an ever increasing problem. In the past, these liquors have been diverted into streams, rivers and lakes where they have given an undesirable dark color to the water body, imparting an objectionable odor and taste to the water and tainting the flesh of the fish and other edible life inhabiting such lakes, rivers and streams. Recent strengthening of environmental impact regulations has placed an ever increasing burden on mill operators to legally and properly dispose of such waste liquors by other means.
Recently, in the United States, mills have been recycling the black liquors, which contain about 10 percent organics, to cookers until the liquors are condensed to a mass containing about 65 percent organics with the balance being inorganic matter and residual water. This mixture then ordinarily is subjected to combustion on a fluidized bed to remove the organic matter, but this process of waste disposal has been beset with problems.
Blackwell, MacKay, Murray and Oldham, "Review of Kraft Foul Condensates", Tappi, Volume 62, No. 10, October 1979, summarizes the sources, quantities, chemical composition and environmental effects of such liquors and presents an extensive bibliography of the published literature about such waste liquors and the problems they present, particularly when the liquors are introduced into fresh water bodies and streams for disposal.
U.S. Pat. Nos. 1,823,440; 3,629,105; 3,766,077; 3,849,328 and 4,157,115 and Shreve, N. R., Chemical Process Industries, Third Edition, 1967, McGraw-Hill, Inc., pages 626, 628, and 635-638, were cited during prosecution of the parent application referenced hereinbefore. None of these relates to the recovery of organic materials from coals or suggests the present process.
Applicant is unaware of any literature or patent publications in any way related to or suggesting any practical use of waste foul condensate for effecting recovery of thermal values and organic materials from coals.